U.S. patent application number 12/664624 was filed with the patent office on 2010-07-29 for electric compressor control device.
This patent application is currently assigned to SANDEN CORPORATION. Invention is credited to Makoto Shibuya.
Application Number | 20100188038 12/664624 |
Document ID | / |
Family ID | 40129518 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100188038 |
Kind Code |
A1 |
Shibuya; Makoto |
July 29, 2010 |
ELECTRIC COMPRESSOR CONTROL DEVICE
Abstract
An electric compressor control device includes: an inverter for
electric compressor motor; a communication microcontroller arranged
in a low-voltage region for transmission of an instruction signal
via a high-speed communication bus; and a control microcontroller
arranged in a high-voltage region and connected to the
communication microcontroller via an insulation element for
transmitting the instruction signal from the communication
microcomputer as an inverter control signal to the inverter. The
power voltage of the communication microcomputer is supplied from a
low-voltage power source. The voltage from the low-voltage power
source is transformed via a transformer and supplied as a power
voltage of the control microcontroller. Thus, it is possible to use
the existing insulation element at an insulation boundary between
the low-voltage region and the high-voltage region so as to surely
supply a predetermined power voltage to the microcontroller for
controlling the inverter, thereby improving the communication
reliability of the entire control device.
Inventors: |
Shibuya; Makoto; (Gunma,
JP) |
Correspondence
Address: |
BAKER BOTTS LLP;C/O INTELLECTUAL PROPERTY DEPARTMENT
THE WARNER, SUITE 1300, 1299 PENNSYLVANIA AVE, NW
WASHINGTON
DC
20004-2400
US
|
Assignee: |
SANDEN CORPORATION
Isesaki-shi, Gunma
JP
|
Family ID: |
40129518 |
Appl. No.: |
12/664624 |
Filed: |
May 27, 2008 |
PCT Filed: |
May 27, 2008 |
PCT NO: |
PCT/JP2008/059704 |
371 Date: |
December 14, 2009 |
Current U.S.
Class: |
318/722 ;
307/9.1 |
Current CPC
Class: |
H02M 2001/0006 20130101;
H02P 27/14 20130101; H02M 7/53875 20130101 |
Class at
Publication: |
318/722 ;
307/9.1 |
International
Class: |
H02P 23/00 20060101
H02P023/00; B60L 1/00 20060101 B60L001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 14, 2007 |
JP |
2007-157327 |
Claims
1. An electric compressor control device comprising: an inverter
which transforms a direct current supplied from a high-voltage
power source into a pseudo alternative current to be supplied as a
drive current for an electric compressor motor; a communication
microcontroller which is arranged in a low-voltage region and to
which an instruction signal is transmitted via a high-speed
communication bus; and a control microcontroller which is arranged
in a high-voltage region and connected to said communication
microcontroller via an insulation element for transmitting said
instruction signal from said communication microcontroller as an
inverter control signal to said inverter, wherein a power voltage
for said communication microcontroller is supplied from a
low-voltage power source, and a voltage from said low-voltage power
source is transformed via a transformer and supplied as a power
voltage for said control microcontroller.
2. The electric compressor control device according to claim 1,
wherein a voltage for driving a gate of said inverter is supplied
also after a voltage from said low-voltage power source is
transformed via said transformer.
3. The electric compressor control device according to claim 1,
wherein said insulation element is a photo-coupler.
4. The electric compressor control device according to claim 1,
wherein said control device is used in an air conditioning system
for vehicles.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to an electric compressor
control device, and specifically, relates to an electric compressor
control device which is suitable as an inverter control device for
an electric compressor used in an air conditioning system for
vehicles.
BACKGROUND ART OF THE INVENTION
[0002] Such a technology for a drive control of a motor of an
electric compressor used in an air conditioning system for
vehicles, for example, is known that a direct current supplied from
a DC power source, such as high-voltage power source, is
transformed by an inverter having multiple switching elements and a
gate driving circuit into a pseudo alternating electric current,
such as a 3-phase AC current, and that pseudo alternating electric
current is applied to a motor for controlling the motor. For
controlling that inverter, a control microcontroller is used, for
example, and an instruction signal from the upper control unit is
sent to the control microcontroller.
[0003] Such a system is constructed as shown in FIG. 2, for
example. The direct current supplied from high-voltage power source
101 is transformed into a pseudo alternating current by inverter
104 having plural switching elements 102 and gate driving circuit
103, and the alternating current is supplied to motor 105 so as to
drive electric compressor 106. An instruction signal sent from the
upper control unit (not shown) via communication bus 107 is
transmitted via a insulation element such as photo-coupler 108 to
control microcontroller 109, so that an instruction signal from
control microcontroller 109 controls gate driving circuit 103 of
each switching element 102 and alternating current voltage supplied
to motor 105. Usually, the area from communication bus 107 to
photo-coupler 108 is located in a low-voltage region 110 (for
example, 12V region), and the area at the side of control
microcontroller 109, inverter 104 and motor 105 from photo-coupler
108 is located in a high-voltage region (for example, 200V region)
for the requirement to drive the motor by high voltage. A boundary
of both voltage regions 110, 111 are formed as insulation boundary
112, and photo-coupler 108 is located in a part of insulation
boundary 112.
[0004] Recently, communication protocols such as CAN (Controller
Area Network) whose communication speeds are high, are being
employed. When those high-speed communication buses are employed,
high-speed communication bus 107 and control microcontroller 109
are directly connected by photo-coupler 108 in an conventional
construction as shown in FIG. 2, however, because the present
photo-couplers are not suitable for high-speed communication, there
is a problem that the response lag of photo-coupler 108 is
generated to cause the communication lag, so that it is difficult
to ensure the communication reliability.
[0005] For that problem, Patent document 1 discloses a technology,
where the signal from a high-speed communication bus is received
once by a communication microcontroller, the signal from the
communication microcontroller is transmitted at a relatively low
communication speed via a normal photo-coupler to a control
microcontroller, and an inverter is controlled by the control
microcontroller. Also in this case, the photo-coupler is located in
an insulation boundary part between a low-voltage region and a
high-voltage region.
[0006] However, in the construction disclosed in Patent document 1,
because the power source voltage for the control microcontroller is
designed to be supplied from a high-voltage power source (Namely,
power source 101 in FIG. 2), if the high-voltage power source is
unconnected the low-speed communication from the communication
microcontroller to the control microcontroller cannot be performed
and a trouble may be caused. In addition, because the power source
voltage for the control microcontroller is taken out of the
high-voltage power source at the inverter side, the length of
wiring in an actual circuit construction becomes long and the
circuit size becomes larger, and a voltage check circuit, etc., to
stabilize the supply voltage is required separately because there
is no guarantee that a predetermined voltage can be stably supplied
to the control microcontroller. Therefore, there is a fear that the
movement of the control microcontroller is not sufficiently stable
and that the communication of the signal is not sufficiently
reliable, consequently.
Patent document 1: JP-A-2004-336907
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] Accordingly, paying attention to the above-described
problems of conventional technologies, an object of the present
invention is to provide an electric compressor control device, in
which existing insulation elements such as a photo-coupler can be
used in an insulation boundary part between a low-voltage region
and a high-voltage region, and a predetermined power source voltage
can be surely supplied to a inverter control microcontroller so
that the signal communication reliability is improved.
Means for Solving the Problems
[0008] To solve the above-described problems, an electric
compressor control device according to the present invention is a
control device comprising:
[0009] an inverter which transforms a direct current supplied from
a high-voltage power source into a pseudo alternative current to be
supplied as a drive current for an electric compressor motor;
[0010] a communication microcontroller which is arranged in a
low-voltage region and to which an instruction signal is
transmitted via a high-speed communication bus; and
[0011] a control microcontroller which is arranged in a
high-voltage region and connected to the communication
microcontroller via an insulation element for transmitting the
instruction signal from the communication microcontroller as an
inverter control signal to the inverter,
[0012] wherein a power voltage for the communication
microcontroller is supplied from a low-voltage power source, and a
voltage from the low-voltage power source is transformed via a
transformer and supplied as a power voltage for the control
microcontroller.
[0013] In this electric compressor control device, because the
signal from the communication bus is received by the communication
microcontroller a high-speed communication can be performed, and
the transmission of the signal from the communication
microcontroller to the control microcontroller is performed via an
existing insulation element which is located in the insulation
boundary part between the low-voltage region and the high-voltage
region so that the low-speed communication can be surely performed
so as to ensure a communication reliability therebetween. Further,
because the power source voltage of the communication
microcontroller is supplied from the low-voltage power source, a
predetermined power source voltage can be stably supplied. The
low-voltage power source voltage transformed via the transformer is
supplied as the power source voltage for the control
microcontroller, and the transformer can make up the insulation
boundary between the low-voltage region and the high-voltage
region, so that a predetermined power source voltage can be stably
supplied surely into the control microcontroller. As a result, both
of the communication microcontroller and the control
microcontroller can be ensured to operate stably so that the
communication reliability of the signal can be improved. Namely,
the communication reliability can be improved while using an
insulation element which exists in the present situation.
[0014] In the above-described electric compressor control device,
it is preferable that the low-voltage power source voltage is
transformed via the transformer and supplied also as a voltage for
the gate driving in the inverter, as shown in an embodiment to
describe later. That makes it possible to stably supply a
predetermined voltage surely as a voltage for the gate drive in the
inverter, too.
[0015] Further, though a photo-coupler is typically used as the
above-described insulation element it is possible to use an element
other than the photo-coupler. In other words, that element is
sufficient if it can form the insulation boundary between
low-voltage region and the high-voltage region and can transmit a
predetermined signal from the communication microcontroller to the
control microcontroller.
[0016] The electric compressor control device according to the
present invention is specifically suitable for an electric
compressor used in an air conditioning system for vehicles. For
example, in the air conditioning system for vehicles, though a low
voltage around 12V is used for general control devices while a high
voltage around 200V is used for an electric compressor which is
used in a refrigeration circuit, the potential difference can be
absorbed by employing the control device configuration according to
the present invention without problems, despite of the great
potential difference.
EFFECT ACCORDING TO THE INVENTION
[0017] In the electric compressor control device according to the
present invention, an existing insulation element can be used for
an insulation boundary part between low-voltage region and the
high-voltage region, the low-speed communication between the
communication microcontroller which receives a signal from the
high-speed communication bus and the control microcontroller can be
ensured stably, and predetermined power source voltage can be
surely supplied into both of the communication microcontroller and
the control microcontroller, so that stable operation can be
ensured and the communication reliability as a whole control device
can be greatly improved.
BRIEF EXPLANATION OF THE DRAWINGS
[0018] FIG. 1 is a schematic circuit diagram of the electric
compressor control device according to an embodiment of the present
invention.
[0019] FIG. 2 is a schematic circuit diagram of a conventional
electric compressor control device.
EXPLANATION OF SYMBOLS
[0020] 1: high-voltage power source [0021] 2: switching element
[0022] 3: gate driving circuit [0023] 4: inverter [0024] 5: motor
[0025] 6: electric compressor [0026] 7: communication bus [0027] 8:
communication microcontroller [0028] 9: photo-coupler as insulation
element [0029] 10: control microcontroller [0030] 11: low-voltage
region [0031] 12: high-voltage region [0032] 13: insulation
boundary [0033] 14: low-voltage power source [0034] 15:
transformer
THE BEST MODE FOR CARRYING OUT THE INVENTION
[0035] Hereinafter, desirable embodiments will be explained
referring to figures.
[0036] FIG. 1 shows an electric compressor control device according
to an embodiment of the present invention, and specifically shows
an example of a control device for an electric compressor which is
provided in a refrigeration cycle of an air conditioning system for
vehicles. In FIG. 1, symbol 1 implies a high-voltage direct current
power source, such as a high-voltage battery mounted in a vehicle.
A direct current supplied from high-voltage power source 1 is
converted by inverter 4 having multiple switching elements 2 and
gate driving circuit 3 into a pseudo alternating current, such as 3
phase alternating current in this embodiment, and the alternating
current is supplied into motor 5 so that electric compressor 6 with
built-in motor 5 is driven. Electric compressor 6 includes a
compressor having only motor 5 as a drive source as well as a
hybrid type compressor having inside the compressor a first
compression mechanism driven by a built-in motor and a second
compression mechanism driven by an external drive source other than
the built-in motor.
[0037] Symbol 7 implies a communication bus which can perform a
high-speed communication. An instruction signal from an upper
control unit, such as ECU (Electric or Electronic Control Unit
mounted in a vehicle: not shown), is transmitted via communication
bus 7 to communication microcontroller 8. The instruction signal
from communication microcontroller 8 is transmitted to control
microcontroller 10 via photo-coupler 9 as an insulation element,
and gate driving circuit 3 of each switching element 2 is
controlled by an instruction signal from control microcontroller
10, so that an alternating current voltage supplied into motor 5 is
controlled. Communication bus 7, communication microcontroller 8
and photo-coupler 9 are located in low-voltage region 11 such as
12V region. Because the motor is required to be driven with a
high-voltage, photo-coupler 9, control microcontroller 10, inverter
4 and motor 5 are located in high-voltage region such as 200V
region. The boundary of both voltage regions 11, 12 is formed as
insulation boundary 13, and photo-coupler 9 is located in the part
of insulation boundary 13. Photo-coupler 9 is an existing
insulation element which can be generally obtained in a market and
which can perform a stable low-speed communication.
[0038] Symbol 14 implies a low-voltage power source such as a
low-voltage battery mounted in a vehicle, and symbol 15 implies a
transformer which can function as a part of insulation boundary 13.
The predetermined voltage (1) from low-voltage power source 14 is
supplied from the primary side of transformer 15 to communication
microcontroller 8 as a power source voltage for communication
microcontroller 8. Further, at the secondary side of transformer 15
(side of high-voltage region 12) the predetermined voltage (2)
transformed by transformer 15 is supplied to control
microcontroller 10 as a power source voltage for control
microcontroller 10. At the same time, in this embodiment the
predetermined voltage (3) transformed by transformer 15 is supplied
to inverter 4 as a voltage for driving the gate of inverter 4.
[0039] In thus constructed electric compressor control device, a
signal from high-speed communication bus 7 is received by
communication microcontroller 8 as it is, so that a high-speed
communication from an upper control unit can be performed. The
signal transmission from communication microcontroller 8 to control
microcontroller 10 is performed through photo-coupler 9 as an
insulation element located in insulation boundary 13 between
low-voltage region 11 and high-voltage region 12, and though at
present there is no photo-coupler suitable for high-speed
communication a stable low-speed communication from communication
microcontroller 8 to control microcontroller 10 can be performed by
photo-coupler 9 which can be obtained at present so that the
communication reliability therebetween can be surely ensured.
Therefore, even a transmission of the instruction signal from
control microcontroller 10 to inverter 4 can be stably performed so
that a desirable inverter control is stably performed with a high
accuracy.
[0040] And because the power source voltage of communication
microcontroller 8 is stably supplied from low-voltage power source
14 without a disturbance, communication microcontroller 8 can be
stably operated with a predetermined power source voltage. A
predetermined voltage transformed through transformer 15 from
low-voltage power source 14 is supplied as a power source voltage
for control microcontroller 10, and transformer 15 can constitute
insulation boundary 13 between low-voltage region 11 and
high-voltage region 12, so that the predetermined power source
voltage is stably supplied surely also to control microcontroller
10. Therefore, because both communication microcontroller 8 and
control microcontroller 10 can be surely operated stably and the
signal communication between communication microcontroller 8 and
control microcontroller 10 can be performed stably by using
existing photo-coupler 9, the communication reliability in a whole
region from communication bus 7 to inverter 4 can be improved.
[0041] Furthermore, because in this embodiment a voltage from
low-voltage power source 14 is transformed into the predetermined
voltage (3) by transformer 15 so as to be supplied as a voltage for
driving the gate of inverter 4, the gate drive control for each
switching element 2 can be stably performed without a disturbance
and the operation of the whole system for control of motor 5 in
electric compressor 6 can be performed stably.
INDUSTRIAL APPLICATIONS OF THE INVENTION
[0042] The electric compressor control device according to the
present invention can be applied as a control device for any
electric compressor which is controlled by a signal from a
communication bus, and specifically, is suitable as a control unit
for an electric compressor used in an air conditioning system for
vehicles.
* * * * *